Wiki Update: Extract Shorelines Guide

[2320sharon]

• For shoreline settings examples: Add screenshots from coastsat extract shoreline

• mention how filtering helps

• Create a use case example for how to extract shorelines

• Add a gif showing how you delete reference shoreline bit

• show what happens if you don't delete interior shorelines

• show how you can change which shorelines are loaded in by changing the ROIs

[2320sharon]

I think the extract shoreline wiki will need to be re-vamped at some point but in the meantime I think its good enough. We should welcome anyone editing it and improve it with each new feature